At birth, a baby’s brain contains 100 billion neurons, roughly as many nerve cells as there are stars in the Milky Way, and almost all the neurons the brain will ever have.

When the number of neurons reaches this magic number, sentience is born, with the birth of a baby. When these neurons start communicating with each other, interconnections/synapses form. The more some routes are used, the stronger they become in the brain, like a memory, a skill, or a reflex.

In less than 500 years, the number of people will reach this magic number.

[…]also at the current growth rate of population of about 1.2% per year, by about 2270 we’ll reach 150 billion. I’d estimate the growth rate will decline over time so we’ll probably reach it around 2500.

Considering the current rate of technology advancement, we can expect people to be scattered throughout the Solar system by then. The technology to instantaneously communicate with any other person will be in common use. At about that time the Human Race, as a whole will become sentient.

Considering the fact that the human race, as a whole, will start evolving technology quicker and quicker, we can expect to have a machine conscience before we reach the Y2500 mark. Considering the short time difference, we can expect the sentient Internet and the sentient Human Race to grow up as a couple of brothers. It will be a very strong symbiosis, because the two brothers will have completely intertwined and symbiotic bodies.

Once such a Solar-system level conscience is born, the exchange of information between its individuals - human or computer - is the equivalent of the firing of neurons.

Thus our best guess is that neurons fire at 0.1-2Hz on average.

If we get a nice round 1Hz - one per second - of neuron fire rate, and compare it to the time human or computer interactions occurs, we can easily see that the difference in 'speed of thought' between the Internet and the Human Race is considerable. On one hand, the thinking speed of the machine conscience will be significantly quicker than that of the human brain. On the other, its human counterpart will be much slower.

We can also consider that once such a sentience is born, its life will be pretty stable, but long in time.

[…] which puts the estimate of the total stars in our galaxy at 100 billion.

We can expect thus, in a Human Race-type of conscience time range, most stars, which are over 100 billion in our galaxy, to develop solar-system level consciences. We can expect these beings to be able to communicate between them, solar-system to solar-system. This in turn could bring, the Milky Way into 'being'.

We know that galaxies are small and big, but we can expect half of them to be equal to or bigger than our galaxy.

Recent estimates of the number of galaxies in the observable universe range from 200 billion (2×1011) to 2 trillion (2×1012) or more. 

Given enough time, we can expect these to be sentient as well, leading to a Universal being.

From here, the last step humans ever thought about is the Multiverse.

The multiverse (or metaverse) is a hypothetical group of multiple separate universes including the universe in which humans live. Together, these universes comprise everything that exists: the entirety of space, time, matter, energy, the physical laws and the constants that describe them.

And considering that the number of Universes in the Multiverse is endless, and our own mortal brushes with other universes, we can expect solid communication possibilities and thus a final, Multiverse entity. Sentient.

That might be the shape of God, or just a 'neuron' of It (Him/Her, really don't make sense at this stage…not to mention the beard), but if it is, I wish It knew that long before it become sentient, a human being though about It. Or maybe we're just a slow galaxy, about to become sentient and participate in this figure, and It is watching us with interest under a mega-microscope. HA!

Speaking of which, do we ever wonder why, among all cells, neurons are special? Maybe their number of molecules is higher than our magic number?

So the number of molecules in a typical human cell is somewhere between 5 million and 2 trillion...

Maybe the connections between these molecules makes these cells special? Sentient to a degree?

Oh, no! No, no! Atoms are not the smallest units of matter.

Particle physicists try to understand the nature of nature at the smallest scales possible. Today, we know that atoms do not represent the smallest unit of matter. Particles called quarks and leptons seem to be the fundamental building blocks - but perhaps there is something even smaller.

Who knows how many times this cycle repeats in the quantum 'world'. Or maybe 'universe'? Oh, wait, quantum logic is weird - it can be any possibility at a given moment. Somehow this sounds like all the possible combinations of Universes in the Multiverse.

We're going in circles it seems!

Oh, one last thing. To put things in perspective, can you imagine the difference in the level of sentient-ness (:D) between a neuron and a human being? Can you scale this up 4 times (Solar-system, Galaxy, Universe, Multiverse)? Maybe put it in a quantum/physical/who-knows-what loop?

[Doru Karacsonyi, 29.07.2018]